Whenever there is lightning and rainstorm, some old buildings are often hit by lightning, causing tragedies such as house destruction and death, but those tall new buildings stand still. Why? This is because at the top of these buildings there is an iron rod more than one meter long - the lightning rod. The lightning rod is not much different from the ordinary iron rod except that a metal wire is connected at its bottom: the metal wire goes deep into the ground along the building and is connected with a large metal plate. This is the overall structure of the lightning rod. It is this simple structure that ensures the safety of the building. We know that lightning is an electrostatic discharge phenomenon. When the cloud accumulates a large amount of charge and approaches the lightning rod, the charge on the cloud is transferred to the metal plate deep in the soil layer through the lightning rod, and finally absorbed by the earth, generating an unlimited amount of "power consumption".

In this way, the building has avoided the "destruction disaster" caused by lightning, and people can safely stay in the house to do their own things. Who invented the lightning rod? He was an outstanding electrical master during the American bourgeois revolution, as well as a famous politician, diplomat, propagandist and writer Franklin. Some people think the lightning rod was invented by the Chinese. Because in the 17th century, a missionary named Marklan found similar devices on the four corners of the roof of some Chinese pavilions. Their structure, principle and function are very similar, except that the iron bar is made into the shape of a dragon. More than 200 years ago, European science was not very prosperous, and theologians still had great authority. Religion believes that lightning strike is God's weapon to punish human beings. It is inevitable that people who do bad things will be struck by lightning. In 1752, after a sensational kite test, Franklin confirmed that lightning was a high-altitude discharge phenomenon, so he had the idea of studying lightning rods.

After hard research, he invented the first lightning rod in the West. The next year, the lightning rod was tried in Branditz. People who are irritated by lightning, hearing that this device can avoid lightning strike, will naturally quickly install it on the roof. However, the church of the city announced: "The sharp pole at the top of the floor is a devil's weapon and an ominous thing. It has offended God and will bring disaster." Under the influence of conservative church forces, some residents took down lightning rods in the dark. After a thunderstorm, some houses without lightning rods were destroyed, the "Holy" Church was on fire, and the houses with lightning rods were safe